| ca9ca1a5 | 29-Jan-2024 |
David Howells <dhowells@redhat.com> |
netfs: Fix missing zero-length check in unbuffered write
Fix netfs_unbuffered_write_iter() to return immediately if
generic_write_checks() returns 0, indicating there's nothing to write.
Note that n
netfs: Fix missing zero-length check in unbuffered write
Fix netfs_unbuffered_write_iter() to return immediately if
generic_write_checks() returns 0, indicating there's nothing to write.
Note that netfs_file_write_iter() already does this.
Also, whilst we're at it, put in checks for the size being zero before we
even take the locks. Note that generic_write_checks() can still reduce the
size to zero, so we still need that check.
Without this, a warning similar to the following is logged to dmesg:
netfs: Zero-sized write [R=1b6da]
and the syscall fails with EIO, e.g.:
/sbin/ldconfig.real: Writing of cache extension data failed: Input/output error
This can be reproduced on 9p by:
xfs_io -f -c 'pwrite 0 0' /xfstest.test/foo
Fixes: 153a9961b551 ("netfs: Implement unbuffered/DIO write support")
Reported-by: Eric Van Hensbergen <ericvh@kernel.org>
Link: https://lore.kernel.org/r/ZbQUU6QKmIftKsmo@FV7GG9FTHL/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240129094924.1221977-3-dhowells@redhat.com
Tested-by: Dominique Martinet <asmadeus@codewreck.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: <v9fs@lists.linux.dev>
cc: <linux_oss@crudebyte.com>
cc: <netfs@lists.linux.dev>
cc: <linux-fsdevel@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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| 843609df | 10-Jan-2024 |
Dan Carpenter <dan.carpenter@linaro.org> |
netfs: Fix a NULL vs IS_ERR() check in netfs_perform_write()
The netfs_grab_folio_for_write() function doesn't return NULL, it returns
error pointers. Update the check accordingly.
Fixes: c38f4e96
netfs: Fix a NULL vs IS_ERR() check in netfs_perform_write()
The netfs_grab_folio_for_write() function doesn't return NULL, it returns
error pointers. Update the check accordingly.
Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/29fb1310-8e2d-47ba-b68d-40354eb7b896@moroto.mountain/
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| 3be0b3ed | 12-Jan-2024 |
Dan Carpenter <dan.carpenter@linaro.org> |
netfs, fscache: Prevent Oops in fscache_put_cache()
This function dereferences "cache" and then checks if it's
IS_ERR_OR_NULL(). Check first, then dereference.
Fixes: 9549332df4ed ("fscache: Imple
netfs, fscache: Prevent Oops in fscache_put_cache()
This function dereferences "cache" and then checks if it's
IS_ERR_OR_NULL(). Check first, then dereference.
Fixes: 9549332df4ed ("fscache: Implement cache registration")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/e84bc740-3502-4f16-982a-a40d5676615c@moroto.mountain/ # v2
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| e2bdb527 | 08-Jan-2024 |
David Howells <dhowells@redhat.com> |
netfs: Fix wrong #ifdef hiding wait
netfs_writepages_begin() has the wait on the fscache folio conditional on
CONFIG_NETFS_FSCACHE - which doesn't exist.
Fix it to be conditional on CONFIG_FSCACHE
netfs: Fix wrong #ifdef hiding wait
netfs_writepages_begin() has the wait on the fscache folio conditional on
CONFIG_NETFS_FSCACHE - which doesn't exist.
Fix it to be conditional on CONFIG_FSCACHE instead.
Fixes: 62c3b7481b9a ("netfs: Provide a writepages implementation")
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20240109083257.GK132648@kernel.org/
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| 807c6d09 | 05-Jan-2024 |
David Howells <dhowells@redhat.com> |
netfs: Fix the loop that unmarks folios after writing to the cache
In the loop in netfs_rreq_unmark_after_write() that removes the PG_fscache
from folios after they've been written to the cache, as
netfs: Fix the loop that unmarks folios after writing to the cache
In the loop in netfs_rreq_unmark_after_write() that removes the PG_fscache
from folios after they've been written to the cache, as soon as we remove
the mark from a multipage folio, it can get split - and then we might see a
fragment of folio again.
Guard against this by advancing the 'unlocked' tracker to the index of the
last page in the folio to avoid a double removal of the PG_fscache mark.
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-afs@lists.infradead.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 92a714d7 | 04-Jan-2024 |
David Howells <dhowells@redhat.com> |
netfs: Fix interaction between write-streaming and cachefiles culling
An issue can occur between write-streaming (storing dirty data in partial
non-uptodate pages) and a cachefiles object being cull
netfs: Fix interaction between write-streaming and cachefiles culling
An issue can occur between write-streaming (storing dirty data in partial
non-uptodate pages) and a cachefiles object being culled to make space.
The problem occurs because the cache object is only marked in use while
there are files open using it. Once it has been released, it can be culled
and the cookie marked disabled.
At this point, a streaming write is permitted to occur (if the cache is
active, we require pages to be prefetched and cached), but the cache can
become active again before this gets flushed out - and then two effects can
occur:
(1) The cache may be asked to write out a region that's less than its DIO
block size (assumed by cachefiles to be PAGE_SIZE) - and this causes
one of two debugging statements to be emitted.
(2) netfs_how_to_modify() gets confused because it sees a page that isn't
allowed to be non-uptodate being uptodate and tries to prefetch it -
leading to a warning that PG_fscache is set twice.
Fix this by the following means:
(1) Add a netfs_inode flag to disallow write-streaming to an inode and set
it if we ever do local caching of that inode. It remains set for the
lifetime of that inode - even if the cookie becomes disabled.
(2) If the no-write-streaming flag is set, then make netfs_how_to_modify()
always want to prefetch instead.
(3) If netfs_how_to_modify() decides it wants to prefetch a folio, but
that folio has write-streamed data in it, then it requires the folio
be flushed first.
(4) Export a counter of the number of times we wanted to prefetch a
non-uptodate page, but found it had write-streamed data in it.
(5) Export a counter of the number of times we cancelled a write to the
cache because it didn't DIO align and remove the debug statements.
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-erofs@lists.ozlabs.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 4088e389 | 05-Jan-2024 |
David Howells <dhowells@redhat.com> |
netfs: Count DIO writes
Provide a counter for DIO writes to match that for DIO reads.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redha
netfs: Count DIO writes
Provide a counter for DIO writes to match that for DIO reads.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 0e4d464c | 05-Jan-2024 |
David Howells <dhowells@redhat.com> |
netfs: Mark netfs_unbuffered_write_iter_locked() static
Mark netfs_unbuffered_write_iter_locked() static as it's only called from
the file in which it is defined.
Signed-off-by: David Howells <dhow
netfs: Mark netfs_unbuffered_write_iter_locked() static
Mark netfs_unbuffered_write_iter_locked() static as it's only called from
the file in which it is defined.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 545b135b | 25-Apr-2022 |
David Howells <dhowells@redhat.com> |
netfs: Export the netfs_sreq tracepoint
Export the netfs_sreq tracepoint so that it can be called directly from
client filesystems/cache backend modules.
Signed-off-by: David Howells <dhowells@redh
netfs: Export the netfs_sreq tracepoint
Export the netfs_sreq tracepoint so that it can be called directly from
client filesystems/cache backend modules.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 100ccd18 | 24-Nov-2023 |
David Howells <dhowells@redhat.com> |
netfs: Optimise away reads above the point at which there can be no data
Track the file position above which the server is not expected to have any
data (the "zero point") and preemptively assume th
netfs: Optimise away reads above the point at which there can be no data
Track the file position above which the server is not expected to have any
data (the "zero point") and preemptively assume that we can satisfy
requests by filling them with zeroes locally rather than attempting to
download them if they're over that line - even if we've written data back
to the server. Assume that any data that was written back above that
position is held in the local cache. Note that we have to split requests
that straddle the line.
Make use of this to optimise away some reads from the server. We need to
set the zero point in the following circumstances:
(1) When we see an extant remote inode and have no cache for it, we set
the zero_point to i_size.
(2) On local inode creation, we set zero_point to 0.
(3) On local truncation down, we reduce zero_point to the new i_size if
the new i_size is lower.
(4) On local truncation up, we don't change zero_point.
(5) On local modification, we don't change zero_point.
(6) On remote invalidation, we set zero_point to the new i_size.
(7) If stored data is discarded from the pagecache or culled from fscache,
we must set zero_point above that if the data also got written to the
server.
(8) If dirty data is written back to the server, but not fscache, we must
set zero_point above that.
(9) If a direct I/O write is made, set zero_point above that.
Assuming the above, any read from the server at or above the zero_point
position will return all zeroes.
The zero_point value can be stored in the cache, provided the above rules
are applied to it by any code that culls part of the local cache.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 41d8e767 | 12-Oct-2023 |
David Howells <dhowells@redhat.com> |
netfs: Implement a write-through caching option
Provide a flag whereby a filesystem may request that cifs_perform_write()
perform write-through caching. This involves putting pages directly into
wr
netfs: Implement a write-through caching option
Provide a flag whereby a filesystem may request that cifs_perform_write()
perform write-through caching. This involves putting pages directly into
writeback rather than dirty and attaching them to a write operation as we
go.
Further, the writes being made are limited to the byte range being written
rather than whole folios being written. This can be used by cifs, for
example, to deal with strict byte-range locking.
This can't be used with content encryption as that may require expansion of
the write RPC beyond the write being made.
This doesn't affect writes via mmap - those are written back in the normal
way; similarly failed writethrough writes are marked dirty and left to
writeback to retry. Another option would be to simply invalidate them, but
the contents can be simultaneously accessed by read() and through mmap.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 62c3b748 | 28-Sep-2023 |
David Howells <dhowells@redhat.com> |
netfs: Provide a writepages implementation
Provide an implementation of writepages for network filesystems to delegate
to.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layto
netfs: Provide a writepages implementation
Provide an implementation of writepages for network filesystems to delegate
to.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| e0ace6ca | 22-Nov-2023 |
David Howells <dhowells@redhat.com> |
netfs, cachefiles: Pass upper bound length to allow expansion
Make netfslib pass the maximum length to the ->prepare_write() op to tell
the cache how much it can expand the length of a write to. Th
netfs, cachefiles: Pass upper bound length to allow expansion
Make netfslib pass the maximum length to the ->prepare_write() op to tell
the cache how much it can expand the length of a write to. This allows a
write to the server at the end of a file to be limited to a few bytes
whilst writing an entire block to the cache (something required by direct
I/O).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 80645bd4 | 11-Oct-2023 |
David Howells <dhowells@redhat.com> |
netfs: Provide netfs_file_read_iter()
Provide a top-level-ish function that can be pointed to directly by
->read_iter file op.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff L
netfs: Provide netfs_file_read_iter()
Provide a top-level-ish function that can be pointed to directly by
->read_iter file op.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 102a7e2c | 16-Feb-2022 |
David Howells <dhowells@redhat.com> |
netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite()
Provide an entry point to delegate a filesystem's ->page_mkwrite() to.
This checks for conflicting writes, then attached any
netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite()
Provide an entry point to delegate a filesystem's ->page_mkwrite() to.
This checks for conflicting writes, then attached any netfs-specific group
marking (e.g. ceph snap) to the page to be considered dirty.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 938e13a7 | 17-Jun-2021 |
David Howells <dhowells@redhat.com> |
netfs: Implement buffered write API
Institute a netfs write helper, netfs_file_write_iter(), to be pointed at
by the network filesystem ->write_iter() call. Make it handled buffered
writes by calli
netfs: Implement buffered write API
Institute a netfs write helper, netfs_file_write_iter(), to be pointed at
by the network filesystem ->write_iter() call. Make it handled buffered
writes by calling the previously defined netfs_perform_write() to copy the
source data into the pagecache.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 153a9961 | 21-Feb-2022 |
David Howells <dhowells@redhat.com> |
netfs: Implement unbuffered/DIO write support
Implement support for unbuffered writes and direct I/O writes. If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are p
netfs: Implement unbuffered/DIO write support
Implement support for unbuffered writes and direct I/O writes. If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary. DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.
Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 016dc851 | 14-Jan-2022 |
David Howells <dhowells@redhat.com> |
netfs: Implement unbuffered/DIO read support
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing
netfs: Implement unbuffered/DIO read support
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing. The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.
The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method. Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.
Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined. As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.
In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| e2e2e839 | 29-Sep-2023 |
David Howells <dhowells@redhat.com> |
netfs: Allocate multipage folios in the writepath
Allocate a multipage folio when copying data into the pagecache if possible
if there's sufficient data to warrant it.
Signed-off-by: David Howells
netfs: Allocate multipage folios in the writepath
Allocate a multipage folio when copying data into the pagecache if possible
if there's sufficient data to warrant it.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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| 7f84a7b9 | 02-Oct-2023 |
David Howells <dhowells@redhat.com> |
netfs: Make netfs_read_folio() handle streaming-write pages
netfs_read_folio() needs to handle partially-valid pages that are marked
dirty, but not uptodate in the event that someone tries to read a
netfs: Make netfs_read_folio() handle streaming-write pages
netfs_read_folio() needs to handle partially-valid pages that are marked
dirty, but not uptodate in the event that someone tries to read a page was
used to cache data by a streaming write.
In such a case, make netfs_read_folio() set up a bvec iterator that points
to the parts of the folio that need filling and to a sink page for the data
that should be discarded and use that instead of i_pages as the iterator to
be written to.
This requires netfs_rreq_unlock_folios() to convert the page into a normal
dirty uptodate page, getting rid of the partial write record and bumping
the group pointer over to folio->private.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
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